Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
655 views
in Circles by (30.3k points)
closed by

The length of the tangent from a point A at a circle, of radius 3 cm, is 4 cm. The distance of A from the centre of the circle is 

A. √7 cm 

B. 7 cm 

C. 5 cm 

D. 25 cm

1 Answer

+1 vote
by (30.5k points)
selected by
 
Best answer

Answer is C. 5 cm

Given: 

AB (say) = 4 cm 

Radius (OB) = 3 cm

Property: The tangent at a point on a circle is at right angles to the radius obtained by joining center and the point of tangency. 

By above property, ∆AOB is right-angled at ∠ABO. 

Therefore, 

By Pythagoras Theorem in ∆POQ, 

OA2 = OB2 + BA

⇒ OA= √(OB2 + BA2

⇒ OA= √(32 + 42

⇒ OA= √(9 + 16) 

⇒ OA = √25 cm 

⇒ OA = 5 cm 

Hence, distance of A from center = 5 cm

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...